A pilot study of electrocortical activity in dysfunctional anger: decreased frontocortical activation, impaired attention control, and diminished behavioral inhibition

Neural activity during the viewing of emotional pictures in veterans with pathological anger and aggression

Anger and aggression are common mental health problems after military deployment. Anger and aggression have been associated with abnormalities in subcortical and cortical levels of the brain and their connectivity. Here, we tested brain activation during the processing of emotional stimuli in military veterans with and without anger and aggression problems. Thirty military veterans with anger and aggression problems and 29 veterans without a psychiatric diagnosis (all males) participated in this study. During an fMRI scan 32 negative, 32 positive and 32 neutral pictures from the International Affective Picture System were presented in intermixed order. The Aggression group showed heightened activity in brain areas including the supplementary motor area, the cingulum and the parietal cortex, in response to stimuli, regardless of category. Furthermore, the Aggression group showed stronger connectivity between the dorsal anterior cingulate cortex (dACC) and the amygdala during the viewing of negative stimuli, and weaker connectivity between dACC and medial prefrontal cortex during the viewing of positive stimuli. Veterans with anger and aggression problems showed enhanced brain response to all stimuli during the task, irrespective of valence and they rated the pictures more likely as negative. We take this to indicate enhanced preparation for action and attention to the presentation of stimuli that could prove to be threatening. Further, group differences in functional connectivity involving the dACC reveal abnormal processing of stimuli with negative and positive valence. In sum, the results point towards a bias towards an enhanced sensitivity to perceived or potential threat in aggression.

The Relation Between Trait Anger and Impulse Control in Forensic Psychiatric Patients: An EEG Study

Inhibitory control is considered to be one of the key factors in explaining individual differences in trait anger and reactive aggression. Yet, only a few studies have assessed electroencephalographic (EEG) activity with respect to response inhibition in high trait anger individuals. The main goal of this study was therefore to investigate whether individual differences in trait anger in forensic psychiatric patients are associated with individual differences in anger-primed inhibitory control using behavioral and electrophysiological measures of response inhibition. Thirty-eight forensic psychiatric patients who had a medium to high risk of recidivism of violent and/or non-violent behaviors performed an affective Go/NoGo task while EEG was recorded. On the behavioral level, we found higher scores on trait anger to be accompanied by lower accuracy on NoGo trials, especially when anger was primed. With respect to the physiological data we found, as expected, a significant inverse relation between trait anger and the error related negativity amplitudes. Contrary to expectation, trait anger was not related to the stimulus-locked event related potentials (i.e., N2/P3). The results of this study support the notion that in a forensic population trait anger is inversely related to impulse control, particularly in hostile contexts. Moreover, our data suggest that higher scores on trait anger are associated with deficits in automatic error-processing which may contribute the continuation of impulsive angry behaviors despite their negative consequences.

Freeze or Forget? Virtual Attack Effects in an Emotional Sternberg Task

Emotionally salient stimuli have the ability to disrupt cognitive processing. This kind of disruption involves effects on working memory and may be related to mental health problems. To explore the nature of such emotional interference on working memory, a Virtual Attack Emotional Sternberg Task (VAEST) was used. Neutral faces were presented as distractors and warning signals, which were sometimes followed by a virtual attack, created by having the neutral face turn angry while the image was enlarged. The attack was hypothesized to have one of two effects: to disrupt cognitive processing and thereby increase interference effects, or to terminate a state of freezing and thereby reduce interference effects. The task was successfully completed online by a sample of 59 students. Results clearly show that the virtual attack caused a reduction of interference relative to no-attack trials. The apparent cognitive disruption caused by emotional distractors may thus reflect freezing, which can be reversed by a freeze-terminating stimulus.

Affective pictures processing is reflected by an increased long-distance EEG connectivity

Analysis of affective picture processing by means of EEG has invaded the literature. The methodology of event-related EEG coherence is one of the essential methods used to analyze functional connectivity. The aims of the present study are to find out the long range EEG connectivity changes in perception of different affective pictures and analyze gender differences in these long range connected networks. EEGs of 28 healthy subjects (14 female) were recorded at 32 locations. The participants passively viewed emotional pictures (IAPS, unpleasant, pleasant, neutral). The long-distance intra-hemispheric event-related coherence was analyzed for delta (1-3.5 Hz), theta (4-7.5 Hz), and alpha (8-13 Hz) frequency ranges for F₃-T₇, F₄-T₈, F₃-TP₇, F₄-TP₈, F₃-P₃, F₄-P₄, F₃-O₁, F₄-O₂, C₃-O₁, C₄-O₂ electrode pairs. Unpleasant pictures elicited significantly higher delta coherence values than neutral pictures (p < 0.05), over fronto-parietal, fronto-occipital, and centro-occipital electrode pairs. Furthermore, unpleasant pictures elicited higher theta coherence values than pleasant (p < 0.05) and neutral pictures (p < 0.05). The present study showed that female subjects had higher delta (p < 0.05) and theta (p < 0.05) coherence values than male subjects. This difference was observed more for emotional pictures than for neutral pictures. This study showed that the brain connectivity was higher during emotional pictures than neutral pictures. Females had higher connectivity between different parts of the brain than males during emotional processes. According to these results, we may comment that increased valence and arousal caused increased brain activity. It seems that not just single sources but functional networks were also activated during perception of emotional pictures.

The trait anger affects conflict inhibition: a Go/Nogo ERP study

To explore the time course of inhibitory control in high trait anger individuals, we recorded and analyzed ERP data relevant to visual Go/Nogo task in high and low trait anger participants. Compared with low trait anger participants, high trait anger participants revealed faster RTs in the Go/Nogo task. The nogo effect of N2 related to conflict monitoring was similar between two groups. While the P3go was larger in high than low trait anger groups, the P3nogo did not differ between two groups. This induced the smaller nogo effect of P3 in high than that in low trait anger group, which is closely related to the actual inhibition of the motor system. These data suggest the reduced later stage of inhibitory processes in high trait anger individuals, implicating the dysfunction of inhibitory control.

The use of single-electrode wireless EEG in biobehavioral investigations

The purpose of this chapter is to introduce novice and intermediate EEG researchers to a convenient and user-friendly EEG system from NeuroSky, Inc. In our recent study we were interested in changes in the frontal cortical EEG activity of healthy adults as a function of accommodative stress during performance of a sustained attention task. We used a commercially available low-cost wireless EEG device from NeuroSky (MindSet), which has a single active Fp1 dry electrode capable of recording research-grade EEG coupled with powerful noise-filtering and data software support. The convenience and ease-of-use of MindSet is further enhanced with validated eSense meters of Attention and Meditation. In this chapter we also provide additional data analytic support for EEG power spectrum using SPSS syntax commonly used in many biobehavioral sciences.